Method of forming the anodes of electrolytic condensers and apparatus for use therein



April 7, 1936. J. E. LILIENFELD 2,036,878

METHOD OF' PORMING THE ANODES OF ELECTROLYTIC CONDENSERS AND APPARATUS FOR USE THEREIN Filed March 20, 1931 2 Sheets-Sheet l ATTO R N EY APl'll 7, 1936. J. E. LILIENFELD 2,036,878

METHOD OF' FORMING THE ANODES OF ELECTROLYTIC CONDENSERS AND APPARATUS FOR USE THEREIN Filed March 20, 1931 2 Sheets-Sheet 2 ATTORNEY Patented Apr. 7, 1936 UNITED ,STATES PATENT OFFICE METHOD OF FORMING THE ANODES OF ELECTROLYTIC CONDENSERS AND APPA- RATUS FOR USE THEREIN The invention relates to a novel procedure for the production of the anodes of electrolytic condensers, and to apparatus utilized in carrying out the same.

It has for an object to simplify this procedure in many of the various operations required on the anodes, particularly the polarization thereof, may be performed while said anodes are mounted on a suitable holding panel which is adapted to receive a plurality of these anodes, thus facilitating the handling of the same in quantity and obviating damage thereto.

A further object of the invention resides in the method of procedure whereby not only is the time of operation greatly reduced but a more perfect anode is obtainable because of greater safety in the handling, and wherein, also, leak losses are reduced to a minimum when the anode is placed in service. The invention has for a still further object to obviate the use of all racks and like supporting means which are generally so utilized as to require troublesome cleaning after each formation operation.

A still further object of the invention resides in the provision of means for affording a substantial contact, and individually with each anode unit, for the formation current.

Further features of the invention reside in the provision of means for retaining automatically the electrolyte at a predetermined temperature; also, in the provision of suitable associated stirring means whereby the uniformity of the electrolyte is maintained throughout the period of` forming the anodes which are arranged to dip therein.

In carrying out the invention, the anodes to be treated are temporarily to be secured in position on a suitable carrying panel therefor with the anode terminals available above the surface of the said carrying panel so thatvelectrical Contact may be made individually to the respective terminals above the surface of the electrolyte in which the anodes are to be formed. The said holding panel with anode units carried thereby may then be handled together in the various op- @rations to be performed on the said anodes. For example, the block of anodes may be subjected to an initial cleaning operation, then formed in a suitable electrolyte and again cleaned and washed, whereupon the same are in proper condition for insertion into a suitable and nal container, and are detached from the supporting panel to be secured in position in the condenser or like container provided. Provision is made, furthermore, whereby the cover member for the condenser container may be carried by the stem or terminal connection of an anode, being located somewhat below the outer end of the terminal and insulated from the anode, which latter and its stem portion are adapted to dip into the electrolyte to be formed or provided with a polarizing lm. It is understood, however, that the anode retaining member or panel is at no time submerged in the electrolyte, but is arranged to be located just above the level of the same in the formation tank, and may comprise Ya suitably shaped sheet of aluminum.

The nature of the invention, however, will best be understood when described in connection with the accompanying drawings, in which:

Fig. l is a vertical section through the novel formation apparatus with electrodes positioned in the forming tank thereof, and taken on the line I-I, Fig. 2.

Fig. 2 is a plan thereof with portions broken away to disclose the underlying parts.

Fig. 3 is a fragmentary elevation and part section illustrating they mounting of a type of anode different from that shown in Figs. l and 2.

Referring to the drawings, I designates a suitable tank or container for an electrolyte I I whose level is designed to be maintained slightly below a panel or cover member I2 for the tank, and is preferably of aluminum and arranged to rest temporarily upon a supporting rim I3 at the upper portion of the said tank. An overflow I4 insures against this level being exceeded, and pro- Vision is made, furthermore, for maintaining substantially constant the temperature of said electrolyte within the tank. For example, a heating coil l5 and a cooling coil i6 may be disposed in the bottom of said tank, the former being designed to receive a heating medium such as steam and the latter cool water, the supplies of the respective media being controlled in any Well-known or special manner through automatic apparatus indicated at il and controlled by a thermally responsive member i8 inserted into the electrolyte. A stirrer mechanism i9 may also be introduced through the panel i2 of the ,n

tank for effecting a substantially uniform temperature throughout the volume of liquid within said tank, and is carried by a contact plate 2t mounted above the panel l2, power for the stirrer mechanism being provided through the flexible shaft 2l.

The Contact plate '20 as well as the stirrer mechanism is preferably suitably suspended, as through cables 22 attached to the said plate by 'the hooks 23, so 'that it may be readily lifted from above the tank to allow of removal and. insertion of the panel I2. Plate 20, moreover, carries a plurality of individual contact-making elements as the rods 25 which are spring-urged by means of springs 26 toward the panel I2 for contactmaking purposes, as will hereinafter be more fully set forth.

The individual elements 25 are electrically interconnected through bus bars 21 to which electric power for effecting the polarization or formation operation is introduced at the terminal lug 28. Provision is made, also, for securing the plate 20 to the tank in vertically disposed relationship thereto as by means of shouldered bolts 29 and nuts 30, said bolts being adapted to fit slots 3| laterally cut inwardly from the edges of the plate to accommodate the bolts.

The panel I2 is provided with a plurality of perforations 35 spaced coaxially with respect to the rods 25 when plate 20 is located by means of the bolts 28 and slots 3I as hereinbefore described. These perforations are designed to mount properly for contact the outer ends of the anodes 36, which anodes are adapted to be supported and to depend therefrom in manner to dip into the electrolyte I I. For example, if the anode be of the type more particularly set forth in my copending application Serial No. 515,885, filed Februarylfi, 1931, in Which there is attached to the riser 31 of an anode, through an intermediate insulator member 38, a metal sleeve 3S, this sleeve extends in part through an openor perforation 35 and projects beyond the top of panel i2. It is, furthermore, provided with a threaded portion 40 designed to engage with a threaded metallic washer 4l fitted into a oorresponding perforation. The flange 42 at the lower end of the sleeve is located below the panel and, in the particular embodiment, affordsthe cover element for a condenser container (not shown) and within which an anode after formation is eventually to be located, as more particularly set forth in my aforesaid copending application. A terminal, such as a wire 43, projects beyond the insulator 38, being bent over at its outer end as indicated, and is designed to receive the lower end or head of a corresponding contact-making element 25 which is resiliently urged thereto by its spring 26 to thus afford temporarily adequate contact with the anode.

Or, reference being had to Fig. 3 of the drawings, an anode 45 may be assembled to have its riser portion 46 arranged to extend through an insulation Washer or gasket 41 which is adapted to be seated in an opening 35 of the panel I2. The riser in .this instance vis provided with a shoulder 48 designed for subsequent engagement with the sealing gasket associated with the condenser cover element (not shown) in the final mounting of the anode in a condenser. A locking nut 49 is also associated with the anode fitting over the threaded end of the riser, and is to be unscrewed to an extent sufficient to lower said shoulder 48 and adjacent riser portion for complete immersion in the electrolyte I3 during the formation operation. This is of particular importance for the reason that when said shoulder is thereafter tightened against a sealing gasket in the condenser assembly, the surface of the same has been completely formed so that there will be no tendency of corrosion in the subsequent operation of the condenser. When not thus formed, satisfactory operation of a condenser ls not possible in that the upper portion of an anode will eventually be eaten through and the anode caused to dro'p oli into'its container. leak and power loss in the meantime, furthermore, constantly increasing.

In thus mounting a plurality of anodes upon a carrying panel such that said anodes may dip simultaneously into an electrolyte contained within the tank upon which said panel is supported, the formation operation may be conducted, through the particular manner of effect.

ing contact with the outer end of a riser anode, to obviate the contact-making elements being affected in any way by the said electrolyte. Furthermore, the panel member provides a convenient rack or holding device for a multiplicity of the respective anodes to enable them to be handled conveniently and safely for the various preliminary operations thereon and operations subsequent to formation.

For example, the anodes thus assembled on the panel may be subjected en masse to a cleansing operation such as is more particularly set forth in my copending application, Serial No. 515,884, filed February 14, 1931. After the cleansing treatment they may be Washed in Waterand then introduced into the form; tion tank, and after formation again washed and finally detached from the panel member for mounting in a suitable container to afford a condenser or rectifier.

It is to be observed that the particular arrangement set forth obviates entirely troublesome cleaning of a rack. member and the like after each formation operation, and the entire procedure is accomplished in a much less time than heretofore and with greater facility. By providing individual contacting means for the respective anodes, a uniform power distribution is had, each anode receiving the proper current and voltage and whereby a more uniform production is attained.

Moreover, contact with an anode terminal may be made directly with a non-polarizable metal suitable for the purpose, such as copper, tin, etc. The end of a rod 25 or the rod as a whole is then constituted of this metal which, even in instances Where the electrolyte should by accident come in contact therewith, could not become polarized and assume a disturbingly high resistance, whereby adequate contact is assured under all conditions. readily assembled and placed in operation, and the danger of damage to an anode during operation is reduced to a minimum.

While throughout the specification and claims the anode formed in accordance with the invention has been referred to as suitable for use in a condenser, it is to be understood, of course, that it is equally suitable for use in electrolytic rectifiers or other apparatus of an electrolytic nature.

I claim:

i. The method of forming anodes for electrolytic condensers, which comprises assembling externally of the forming tank an anode in its final holding fixture, loosening the anode to lower its riser portion relatively to the fixture somewhat below the normal position when in service, removably mounting the anode on the forming tank to dip into the electrolyte and immerse substantially the lowermost portion, applying electric current to the anode externally of the immersed portion, then removing the anode from Furthermore, the entire apparatus is the electrolyte, and finally tightening theanode trolyte, a conductive panel removably supportable on the tank and adapted to temporarily mount a plurality of polarizable anodes to dip into the electrolyte, the said anodes each having a terminal element projecting above the panel, means to insulate the anodes individually from the panel. and means adapted to make electrical contact individually with the respective terminal elements for supplying electric current to the anodes.

3. Apparatus for forming anodes for electrolytic condenser-s, comprising a tank for electrolyte, a conductive panel removably supportable on the tank and adapted to temporarily mount a plurality of polarizable anodes to dip into the electrolyte, the said anodes each having a terminal element projecting above the panel, means to insulate the anodes individually from the panel, and non-polarizable means adapted to make electrical contact individually with the respective terminal elements for supplying electric current to the anodes.

4. Apparatus for forming anodes for electrolytic condensers, comprising a tank for electrolyte, an aluminum panel removably supportable on the tank and adapted to temporarily mount a plurality of polarizable anodes to dip into the electrolyte, the said anodes each having a terminal element projecting above the panel, means to insulatethe anodes individually from the panel, and non-polarizable means adapted to make electrical contact individually with the respective terminal elements for supplying electric current to the anodes.

5. Apparatus for forming anodes for electrolytic condensers, comprising a tank for electrolyte, a conductive panel removably supportable on the tank and adapted to temporarily mount a plurality of polarizable anodes to dip into the electrolyte, the said anodes each having a terminal element projecting' above the panel, means to insulate the anodes individually from the panel, and a plurality of means mounted above the panel for making contact individually with the respective terminal elements.

6. Apparatus for forming anodes for electrolytic condensers, comprising a tank for electrolyte, a conductive panel removably supportable on the tank and adapted to temporarily mount a plurality of polarizable anodes to dip into the electrolyte, the said anodes each having a terminal element projecting above the panel, means to insulate the anodes individually from the panel, and a plurality of resilient contact means mounted above the panel for making contact individually with the respective terminal elements.

'7. Apparatus for forming anodes for electrolytic condensers, comprising a tank for electrolyte, a conductive panel removably supportable on the tank and adapted to temporarily mount a plurality of pclarizable anodes to dip into the electrolyte, the said anodes each having a terminal element projecting above the panel, means to insulate the anodes individually from the panel, a contact-making member embodying 9. Apparatus for forming anodes for electro-` lytic condensers, comprising a tank for electrolyte, temperature-regulating coils mounted within the tank for respective heating and cooling fluids adapted to maintain a predetermined temperature of the electrolyte therein, thermally responsive means subjected to the electrolyte in the tank for controlling the supply of heating and cooling fluids to the regulating coils, stirrer means for the electrolyte, a panel removably supportable on the tank and adapted to mount temporarily a plurality of polarizable anodes to dip into the electrolyte, the said anodes each having a terminal element projecting above `the'l panel, and means adapted to make electrical contact individually with the respective terminal elements for supplying electric current to the anodes.

l0. Apparatus for forming anodes for electrolytic condensers, comprising a tank for electrolyte, a panel member having a plurality of threaded openings and removably supportable on the tank, polarizable anodes with respective threaded ends adapted to be screwed info the said panel openings to dip into the electrolyte and having corresponding terminals extending beyond the threaded portion, and contact-making means adapted for individual engagement with the respective terminals.

11. Apparatus for forming anodes for electrolytic condensers, comprising a tank for electrolyte, a panel member having a plurality of threaded openings and removably supportable on the tank, polarizable anodes having an end metal sleeve with exterior threads and bottom flange, said sleeve being adapted to be threaded into the corresponding panel openings and its attached anode adapted to dip into the electrolyte, an insulating bushing between an anode and its sleeve, and said anode having a terminal element extending beyond the bushing, and contactmaking means adapted for individual engagement with the respective terminals.

l2. Apparatus for forming anodes for electrolytic condensers, comprising a tank for electrolyte, a panel member having a plurality of threaded openings and removably supportable on the tank, polarizable anodes having an end metal sleeve with exterior threads and bottom ange, said sleeve being adapted to be threaded into the corresponding panel openings and the attached anode adapted to ydip into the electrolyte, an insulating bushing between an anode and its sleeve, extending beyond the latter and containing a terminal from the anode extending beyond the outer end of said bushing, and a contactmaking member mounted abo-ve the tank and panel and embodying a plurality of resiliently mounted contact-making elements adapted to register with the respective anode terminals.

i3. Apparatus for forming anodes for electrolyti'c condensers, comprising a tank for electro- -a panel removably supportable on the tank and provided with a plurality of perioratlons,

u tapped washers in the respective perforations,

14. The method of forming polarlzable anodes,

which comprises insulating externally of the forming tank an anode in its final holding tix-` ture, mounting a plurality of the anodes upon a common supporting panel above the surface of a suitable electrolyte to cause the anodes to dip therein, and forming the anodes by introducingelectric current simultaneously to all of the anodes by individually contacting the anodes above the panel.

15. The method of forming polarizable anodes, which comprises insulating externally of the forming tank an anode in its final holding fixture, mounting a plurality of the anodes upon a common supporting panel above the surface of a suitable electrolyte to cause the anodes to dip therein, and forming the anodes by introducing electric current simultaneously to all .of the anodes by individually contacting the anodes externally of the electrolyte above the panel through a non-polarizable contacting element.

16. The method of forming anodes for electrolytic condensers, which comprises assembling ex-= ternally of the forming tank an anode in its nal holding fixture, loosening the anode to lower its riser portion relatively to the xture somewhat below the normal position when in service, removably mounting the anode on the forming tank to dip into the electrolyte and immerse substantially the` lowermost portion, applying electric current to the anode externally of the immersed portion, then removing the anode from the electrolyte, and nally tightening the anode to its holding fixture and ydetaching it from the forming tank.

17. The method of forming the anodes forl elec trolytic condensers, which comprises insulating from'one another and externally of :he polarizing electrolyte a plurality of anodes by individually insulating an anode in its nal holding nxture and assembling a plurality of the 'iixtures upon a panel common thereto, introducing the anodes simultaneously into an electrolyte with cathode common to all of said anodes and while supported on the panel, and applying an electric current to the outer ends of the anodes by simultaneously contacting the same above the panel and externally of the electrolyte.

18. The method of forming the anodes for electrolytic condensers, which comprises insulating from one another and externally of the polarizing electrolyte a plurality of anodes by individually insulating an anode in its final holding ixture and assembling a, plurality of the ilxtures upon a panel common thereto, cleansing the anodes, introducing the anodes simultaneously into an electrolyte with cathode common to all of said anodes and while supported on the panel, applying an electric current to the outer ends of the ano-des by simultaneously contacting the same above the panel and externally of the electrolyte, removing the panel, washing the anodes, and then detaching the said anodes from the panel and readjusting them in their respective holding xtures.

i9. The method of forming polarizable anodes, which comprises mounting externally of a suitable electrolyte a plurality of individual anodes to dip partly therein with cathode common to all of said anodes and with the respective free ends of the latter exposed for contact, temporarily supporting said free ends externally of the electrolyte, and forming simultaneously all of said anodes by introducing electric current thereto by individually and simultaneously mechanically contacting said free ends externally of the electrolyte.

JULIUS EDGAR LILIENFELD. 

